Currently, the European Telecommunications Standards Institute (European Telecommunications Standards Institute, ETSI for short) has established a Network Function Virtualization Industry Specification Group (Network Function Virtualization Industry Specification Group, NFV ISG for short) for the purpose of using a virtualization technology of an Internet technology (Internet Technology, IT for short), so that universal hardware can implement some network functions. This requires that a network function should run on universal hardware in a form of a virtualized network function (Virtualized Network Function, VNF for short), and the VNF herein is a virtualized entity having a network function. For example, if a VNF has a mobility management entity (Mobility Management Entity, MME for short) function, this VNF is a virtual MME. In addition, the VNF is deployed on one or more virtual machines (Virtual Machine, VM for short), so that the VNF runs and becomes a VNF instance, which is known as an instantiation process of the VNF.
Currently, in a network function virtualization management and orchestration (Network Function Virtualization Management and Orchestration, NFV MANO for short) architecture discussed in standards, referring to FIG. 1, the architecture may include an operation support system (Operation Support System, OSS for short) or a business support system (Business Support System, BSS for short), a VNF, a network function virtualization infrastructure (NFV Infrastructure, NFVI for short), a virtualized infrastructure manager (Virtualized Infrastructure Manager, VIM for short), an NFV orchestrator (NFV Orchestrator, NFVO for short), and a VNF manager (VNF Manager, VNFM for short). The VNF corresponds to a virtualized physical network function (Physical Network Function, PNF for short). For example, the VNF may be a virtual core network, such as EPC (Evolved Packet Core, EPC for short) node, that is, it may be a virtual MME or a virtual service gateway (Service Gateway, S-GW for short). The NFVI includes hardware resources, virtual resources, and a virtual layer. The VIM is configured to control and manage a virtualized entity. The NFVO is responsible for orchestrating and managing NFVI resources on a network side, and implementing an NFV service topology in the NFVI. The VNFM is responsible for managing a lifecycle of a VNF instance. In addition, the NFV MANO further includes four repositories, namely, a network service catalog (Network Service Catalog, NS Catalog for short), a VNF catalog, an NFV instance repository (Instance), and an NFVI resource repository. A network service descriptor (NS Descriptor, NSD for short) for describing a network service (Network Service, NS for short) is stored in the NS Catalog, and actually the NS herein may be a virtual EPC, including at least one VNF forwarding graph (VNF Forwarding Graph, VNFFG for short), where one VNFFG includes at least one VNF and virtual links between these network functions. The VNFFG is mainly configured to describe a service flow between the network functions. A VNF descriptor (VNF Descriptor, VNFD for short) for describing a hardware resource requirement of software in the VNF is stored in the VNF catalog. An NS instance and a VNF instance are stored in the NFV instance repository. An NFVI resource status is stored in the NFVI resource repository.
In the prior art, when a new function is introduced into the VNF, a software version in the VNF needs to be upgraded. In an upgrade process, a sender (Sender) sends an upgrade request of the VNF to the NFVO, and the NFVO sends the upgrade request to the VNFM, so that the VNFM instructs a VM corresponding to the VNF to prepare for upgrade and data migration; after obtaining a response message from the VM, the VNFM initiates a VNF instantiation process to obtain a new VNF instance (software in the VNF instance is of an upgraded software version), installs to-be-migrated data in the upgraded new VNF instance, and performs subsequent processing; and finally, the VNFM performs a switching process, that is, the upgraded VNF instance is powered on and goes online, and a VNF instance of an old version is powered off and goes offline.
However, the VNF upgrade process in the prior art may interrupt running of the VNF instance of the old version and therefore affect a service in the VNF instance of the old version. In particular, some services that have higher real-time requirements are greatly affected.